COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Restraint Equipment AD/RES/21 Pacific Scientific Lap Belt Assemblies 1/88 Applicability: All Pacific Scientific lap belt assemblies P/N 1107177 (all dash numbers). Requirement: Inspect all Pacific Scientific TSO C22f lap belt assemblies, part number 1107177 (all dash numbers), to determine if they have part number 1106294-01 retractor shafts made of the correct material. This is determined by visual examination of the end of the shaft. If the colour is gold anodise, the shaft is acceptable. If the colour is dull battleship grey anodise, the shaft must be replaced. FAA AD 87-20-05 dated 26 October 1987 refers. Pacific Scientific Safety Advisory Letter on Mark V Reel Lap Belt Assembly refers. Compliance: Inspect prior to the issue of the Maintenance Release after 30 June 1988. Replace defective shafts within 5 hours time in service. Background: Pacific Scientific has found that batches of inertia reel shafts fitted to the applicable lap belt assemblies were manufactured using incorrect material. These shafts have failed at loads below that required by TSO C22f.